1. Field of the Invention
The present invention relates to high frequency electronics. More specifically, the present invention relates to the integration and impedance matching of systems formed from high impedance nanoscale devices.
2. Description of Related Art
Carbon nanotubes were discovered in the early 1990s as a product of arc-evaporation synthesis of fullerenes. Scientists have since determined that carbon nanotubes have extraordinary physical characteristics, and their potential use in many different applications has attracted much attention. For example, field effect transistors formed using carbon nanotubes provide a linear response at extremely low power. Their linearity, and small size, makes the use of carbon nanotube field effect transistors ideal for low-power, highly linear systems such as radar and communications receivers or any battery powered device.
Due to their small size and structure, carbon nanotube field effect transistors are able to source only a small amount of RF current. Therefore, it is difficult to engineer systems from carbon nanotube field effect transistors that efficiently interface with the high current levels seen in the everyday world. Specifically, the input impedance of a carbon nanotube field effect transistor is capacitive, and this small capacitance gives carbon nanotube field effect transistors an input impedance on the order of 10 kΩ or more. Similarly, these devices have a very large output impedance as well. Because traditional transmission lines and loads are generally in the range of 5Ω-500Ω, there exists an inherent impedance mismatch between nanoscale devices and traditional high frequency devices and systems. Traditional matching techniques employing transmission line, capacitors, inductors, and resistors require the use of networks that can be large, extremely lossy, and/or narrow band and are therefore unsuitable for many high frequency applications.
Thus, there remains a need for systems and methods to effectively use high impedance carbon nanotube devices in high frequency systems.